AKAI M-9

Commentary

Stereo tape recorder with built-in cross-field head and all-silicon transistor amplifier.

Cross-field head is used for the head part.
In this conventional recording method, both a signal current and a bias current are applied to the recording head. Once recorded, the signal is erased or weakened by the influence of a wide bias magnetic field. This phenomenon is particularly noticeable at high frequencies.
In order to solve this problem, the cross-field method applies the signal current to the recording head and the bias current to the external bias head. Since these heads are displaced relative to each other in the specified spatial position, the signal recorded on the tape is recorded without being affected by the bias magnetic field.

Hysteresis synchronous 2-speed motor is used for the mechanism part.

Equipped with a track selector knob for easy switching between stereo and monaural.

Equipped with tone control function and bass switch to emphasize low range.

It has an equalizer for each tape speed.

Equipped with a tape shifter that operates during fast forward and rewind.

Equipped with a 4-digit counter with reset button and two VU meters.

Equipped with a tape cleaner.
This cleaner removes dust and iron oxide powder attached to recording tapes, and eliminates the squeaking noise generated during recording and playback.

Equipped with automatic stop, automatic shut-off, automatic pinch roller release mechanism.
When the tape reaches the fully wound or unwound area, the automatic shut-off lever drops and the tape stops automatically. The automatic shut-off mechanism stops only the operation of the mechanism, and the automatic shut-off mechanism turns off the power supply at the same time. In either case, the pinch roller automatically separates from the capstan shaft, preventing the rubber from wearing out and the shaft from being deformed while the pinch roller remains in close contact with the capstan shaft. This is the automatic pinch roller release.

Equipped with automatic lever release.
With automatic lever release, when the tape reaches the end of the tape, the automatic shut-off lever falls as soon as the tape is fully wound, and the fast-forward / rewind knob automatically and the tape stops.

Equipped with universal power supply voltage switching device.

The speaker unit is equipped with two 10 cm cone speakers.

Both horizontal and vertical specifications are possible.

There were 2 kinds of variations, a leather case and a walnut case.

Model Rating

Type	Tape deck
Tape speed	4.75cm/s, 9.5cm/s, 19cm/s 38cm/s (Possible with attached adapter)
Wow flutter (Playback only)	0.15% RMS or less (19cm/s) 0.25% RMS or less (9.5cm/s) 0.35% RMS or less (4.75cm/s)
Frequency characteristic	30 Hz ~ 23 kHz ± 3 dB (19cm/s) 30 Hz ~ 18 kHz ± 3 dB (9.5cm/s) 30 Hz ~ 9 kHz ± 3 dB (4.75cm/s)
Total harmonic distortion factor	2% or Less (1 kHz, 0 VU)
Signal-to-noise ratio	50 dB or more
Input level	Mic : 0.5 mV or more Line : 60 mV or more
Output	Undistorted output (maximum) : 15W + 15W Music power : 20W + 20W
Recording (playback) compensation characteristics	NARTB characteristics
Recording level indication	2 x VU meter
Recording system	4-track stereo / monaural, cross field bias system (Japanese Patent No. 451906)
Fast-forward and rewind method	90 seconds each (370m tape, 50 hz) 75 seconds each (370m tape, 60 hz)
Recording time	Stereo : 8 hours (370m tape, 4.75cm/s) Mono : 4 hours (370m tape, 4.75cm/s)
Heads	Recording / Playback : 4-track stereo / mono (1.2k Ω at 1 kHz) Bias head : 4-track stereo (500 Ω at 60 kHz) Erase Head : 4-track stereo (500 Ω at 60 kHz)
Motor	Two hysteresis synchronous 2 speed motors
Spekers	2 x 10 cm cone shapes
Semiconductor used	Transistor : 20 Thermistor : 4 Rectifiers : 4
Power supply voltage	6-step switching between 100 V ~ 240 V AC, 50Hz/60Hz
Power consumption	100VA
External dimensions	Width 340x Height 508x Depth 240 mm
Weight	19kg
Attachment	One 7-inch demonstration tape 1 x 7 Empty Reel 1 adapter kit for 38cm/s 2 pads for tape cleaner Silicon Oil x1 Fuse (for amplifier) x2 1 fuse (for power supply)